Dock boards and loading ramps have heretofore been provided for installation in loading docks to facilitate transport and transfer of materials or articles from a vehicle, such as a truck or trailer, that may be backed up to the loading dock for loading or unloading. These loading ramps, in general, include a horizontal platform which is mounted in a pit or recessed in the loadingdock for upward swinging movement. In a stored position, the platform or ramp is maintained or held in a horizontal plane so as to form a continuation of the loading dock surface. In this configuration, the ramp does not obstruct normal traffic on the dock. Various mechanisms are included in such loading ramps to effect the pivoting or swinging of the dock to an elevated position. Once the ramp has been raised, it is then lowered to align with the bed of the truck or trailer. To complete the transporting surface into the interior of a truck or trailer, the ramp is normally provided with a forwardly or outwardly projecting lip that forms a bridge between the ramp and the bed of the truck. This lip is pivoted on a hinge element at the outer end of the platform or ramp and is movable between a downwardly dependingly, stored position and an outwardly projecting position where it may extend into the interior of the truck.
Loading ramps of this type are also provided with a lock means that is effective in securing or maintaining he pivoted lip in an outwardly projecting position. The purpose of this lock is to maintain the lip in this outwardly extending relationship to the ramp so that it will then overlie and project into the interior of the truck as the ramp itself is lowered or swung downwardly to a load transferring position. Once the loading or unloading operation has been completed, the truck or vehicle is driven away from the dock and the loading ramp then lowered to its horizontal stored position. During the operation of the ramp, provision is usually made to permit the lip to be unlocked and released to enable the lip to swing to its vertical or downward depending position for storage. An example of such a structure is shown in U.S. Pat. No. 3,982,295 issued Sept. 28, 1976 to Peter B. Burnham.